Albano Helena, Todorov Svetoslav D, van Reenen Carol A, Hogg Tim, Dicks Leon M T, Teixeira Paula
Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr António Bernardino de Almeida, Porto, Portugal.
Int J Food Microbiol. 2007 May 10;116(2):239-47. doi: 10.1016/j.ijfoodmicro.2007.01.011. Epub 2007 Feb 20.
Lactic acid bacteria were isolated from "Alheira" sausages that have been sampled from different regions in Portugal. The sausages were produced according to different recipes and with traditional starter cultures. Two isolates (HA-6111-2 and HA-5692-3) from different sausages were identified as strains of Pediococcus acidilactici. Each strain produces a bacteriocin, designated as bacHA-6111-2 and bacHA-5692-3. Both bacteriocins are produced at low levels after 18 h of growth in MRS broth (3200 AU/ml against Enterococcus faecium HKLHS and 1600 AU/ml against Listeria innocua N27). BacHA-6111-2 and bacHA-5692-3 are between 3.5 kDa and 6.5 kDa in size, as determined by tricine-SDS-PAGE. Complete inactivation or significant reduction in antimicrobial activity was observed after treatment of cell-free supernatants with proteinase K, pronase and trypsin. No change in activity was recorded when treated with catalase. Both bacteriocins are sensitive to treatment with Triton X-114 and Triton X-100, but resistant to Tween 20, Tween 80, SDS, Oxbile, NaCl, urea and EDTA. The bacteriocins remained stable after 2 h at pH 6.0. A decrease in antibacterial activity was recorded after 60 min at 100 degrees C. After 60 min at 80 degrees C, 60 degrees C and 25 degrees C the antibacterial activity against L. innocua N27 decreased by 25%. Addition of bacHA-6111-2 and bacHA-5692-3 (1600 AU/ml) to a mid-log (5-h-old) culture of L. innocua N27 inhibited growth for 7 h. Addition of the bacteriocins (3200 AU/ml) to a mid-log (5-h-old) culture of E. faecium HKLHS repressed cell growth. The bacteriocins did not adhere to the surface of the producer cells. Both strains contain a 1044 bp DNA fragment corresponding in size to that recorded for pediocin PA-1. Sequencing of the fragments from both bacteriocins revealed homology to large sections of pedA (188 bp), pedB (338 bp) and pedC (524 bp) of pediocin PA-1 and the bacteriocins are considered similar to pediocin PA-1.
乳酸菌是从葡萄牙不同地区采集的“阿尔黑拉”香肠中分离出来的。这些香肠是按照不同的配方并使用传统发酵剂制作而成的。从不同香肠中分离出的两株菌（HA - 6111 - 2和HA - 5692 - 3）被鉴定为嗜酸片球菌菌株。每株菌都产生一种细菌素，分别命名为bacHA - 6111 - 2和bacHA - 5692 - 3。在MRS肉汤中培养18小时后，两种细菌素的产量都较低（对粪肠球菌HKLHS的抑菌活性为3200 AU/ml，对无害李斯特菌N27的抑菌活性为1600 AU/ml）。经tricine - SDS - PAGE测定，bacHA - 6111 - 2和bacHA - 5692 - 3的大小在3.5 kDa至6.5 kDa之间。用蛋白酶K、链霉蛋白酶和胰蛋白酶处理无细胞上清液后，抗菌活性完全丧失或显著降低。用过氧化氢酶处理后，活性没有变化。两种细菌素对Triton X - 114和Triton X - 100处理敏感，但对吐温20、吐温80、十二烷基硫酸钠、牛胆汁、氯化钠、尿素和乙二胺四乙酸具有抗性。细菌素在pH 6.0条件下2小时后仍保持稳定。在100℃处理60分钟后，抗菌活性降低。在80℃、60℃和25℃处理60分钟后，对无害李斯特菌N27的抗菌活性降低了25%。向无害李斯特菌N27的对数中期（培养5小时）培养物中添加bacHA - 6111 - 2和bacHA - 5692 - 3（1600 AU/ml）可抑制其生长7小时。向粪肠球菌HKLHS的对数中期（培养5小时）培养物中添加细菌素（3200 AU/ml）可抑制细胞生长。细菌素不附着在产生菌细胞的表面。两株菌都含有一个1044 bp的DNA片段，其大小与记录的片球菌素PA - 1的片段大小一致。对两种细菌素的片段进行测序后发现，它们与片球菌素PA - 1的pedA（188 bp）、pedB（338 bp）和pedC（524 bp）的大部分区域具有同源性，因此这两种细菌素被认为与片球菌素PA - 1相似。
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